1. Field of the Invention
This invention relates to an image forming apparatus using the electrophotographic art and to a process cartridge removably mountable to a body of this image forming apparatus.
The term "image forming apparatus" covers, for example, electrophotographic copying apparatuses, electrophotographic printers (such as LED printers and laser beam printers), electrophotographic facsimile apparatuses, etc.
2. Description of the Related Art
In an image forming apparatus using the electrophotographic image forming process, there has heretofore been adopted a process cartridge system in which an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally made into a cartridge and the cartridge is made removably mountable to the body of the image forming apparatus. According to this process cartridge system, the maintenance of the apparatus can be done by a user himself without resorting to a serviceman and therefore, the operability of the apparatus could be markedly improved. So, this process cartridge system is widely used in image forming apparatuses.
Now, the distance between a photosensitive member and a developing sleeve must usually be kept at the order of several hundred p m. In order to keep this distance, rollers (spacers) slightly larger than the diameter of the sleeve are mounted near the opposite ends of the developing sleeve and these rollers are abutted against the opposite ends of the photosensitive drum. However, if a toner adheres to the surface of the photosensitive drum against which the rollers are abutted, the distance between the developing sleeve and the photosensitive drum will not be correct.